Which of these enhances low-speed flight capabilities?

High-lift devices are specifically designed to improve an aircraft's aerodynamic performance at lower speeds, which is crucial during phases of flight such as takeoff and landing. These devices work by increasing the camber of the wing or altering its configuration to enhance lift. They include flaps, slats, and slots, which all serve to expand the critical angle of attack and reduce stall speeds, allowing the aircraft to fly safely at slower speeds.

When activated, high-lift devices effectively increase the wing's surface area and enhance airflow over the wing, which significantly improves the lift generated at lower airspeeds. This capability is vital for ensuring safe operations at lower speeds, where many accidents could occur if the aircraft were to stall.

In contrast, primary flight controls mainly involve ailerons, elevators, and rudders, which are primarily used for controlling the aircraft's attitude and direction during flight, rather than enhancing lift at low speeds. Auxiliary flight controls also help with handling characteristics but do not directly increase lift like high-lift devices do. Trim controls, on the other hand, are used to relieve control pressures and maintain level flight, but they do not contribute directly to enhancing low-speed flight capabilities.